Created
October 21, 2022 18:02
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Simple JavaScript for loops
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// Alternate for loop that is more of a functional style | |
// `fr` accepts two arguments. | |
// The first argument expects an Array (to get the length of it) or a number. Passing in an array is similar to `myArray.forEach()`. | |
// The second argument is a function with the signature `(currentIteration, totalIterations)` | |
const fr = (iterationsOrArray, fn) => { | |
if (typeof iterationsOrArray !== 'number'&& !Array.isArray(iterationsOrArray)) { | |
throw new TypeError('Invalid argument: expected an `Array` or `number` for the first argument'); | |
} | |
let iterations = (Array.isArray(iterationsOrArray) ? iterationsOrArray.length : iterationsOrArray); | |
if (typeof fn !== 'function') { | |
throw new TypeError('Invalid argument: expected a `function` for the second argument'); | |
} | |
for (let i = 0; i < iterations; i++) { | |
fn(i, iterations); | |
} | |
} | |
// Usage examples | |
// Loop an arbitrary number of times | |
fr(5, (i) => console.log(i)); | |
// 0 | |
// 1 | |
// 2 | |
// 3 | |
// 4 | |
// Loop over every entry in an array | |
const myArray = [1,2,3]; | |
let text = ''; | |
fr(myArray, (i, iterations) => text += `iteration ${myArray[i]} of ${iterations}\r\n`); | |
console.log(text); | |
// iteration 1 of 3 | |
// iteration 2 of 3 | |
// iteration 3 of 3 |
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